British and French diplomats told The Associated Press on Tuesday that officials are preparing a second round of sanctions on top of an initial round imposed last week. Those deemed responsible for undermining Ukrainian territorial integrity and promoting instability would suffer travel bans and frozen assets.

French Foreign Minister Laurent Fabius says these sanctions could be in place later this week. If Russia doesn’t pull back from Crimea, ‘‘there is a set of sanctions that will take effect as of this week and that will consist of freezing the personal assets of Russians and Ukrainians and visa restrictions,’’ Fabius told France-Inter radio on Tuesday.

However, the EU is likely to wait to see whether Crimea declares itself independent or is annexed by Russia before deciding on new sanctions. A vote in Crimea on Sunday could be decisive, and EU foreign ministers are scheduled to meet the next day in Brussels.

German Foreign Minister Walter Steinmeier, whose country has been more cautious than Britain and Russia’s immediate neighbors, said Tuesday that the EU will decide on further sanctions by Monday if the situation doesn’t improve.

While the U.S. has sent military hardware to the region and authorized visa bans and asset freezes, many Europeans are wary of the prospect of war on their eastern doorstep and of antagonizing Russia, an important trading partner and energy supplier.